Unable to delete Forticlient vpn from backup drive

Hello all,

I was enrolled in a university that had a partnership with fortinet regarding the forticlient vpn. When I switched universities I uninstalled the forticlient app (Mac user) with the uninstaller.

Unbeknownst to me, both the app and the uninstaller were backed up in a back up before. That hard drive is now full and I am looking to remove older back ups, the one from 2023 with the vpn as well.

I am unable to delete the forticlient app or the uninstaller from the back up drive, as both are protected and I cannot override that setting. I tried dragging the uninstaller back to my desktop (i.e. restoring it) however it doesn't detect the vpn as being on my Mac and now the uninstaller is stuck not only on the back up drive but on my desktop too.

I've tried every internet solution I could find (dragging both the application and the uninstaller to the bin, right-clicking and clicking on place in bin, using sudo rm -rf), but none of these resolve the problem that I cannot delete these apps (error message roughly translated: cannot delete this app as it is protected).

I am grateful for any interaction and help in advance :)